Human Genetics and Disorders

If an affected father passes a trait to all his daughters, it suggests the trait is X-linked dominant, as he passes his only X chromosome to all his daughters.

Sickle cell anemia is an autosomal recessive disorder. An individual must have two copies of the recessive allele (ss) to express the disease.

Regulatory regions control gene expression. Mutations here can change the rate of transcription (how much protein is made) or disrupt the binding sites entirely, preventing expression.

'Philadelphia chromosome' is found in the patient suffering from leukaemia. The main cause is a genetic abnormality in chromosome 22 of leukaemia cancer cells. The chromosome is short due to a reciprocal translocation between chromosome 9 and chromosome 22 and contains a fusion gene called BCR-ABL1 which is juxtaposed onto the BCR gene of chromosome 22, coding for a hybrid protein, a tyrosine kinase signalling protein which causes rapid multiplication of the cell.

An oncogene is a gene that has the potential to cause cancer. In tumour cells, they are often mutated or expressed at high levels. Activated oncogenes can cause those cells designated for apoptosis (programmed cell death) to survive and proliferate instead. Most oncogenes began as proto-oncogenes which are normal genes involved in cell growth and proliferation or inhibition of apoptosis.

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. A proto-oncogene is a normal gene that could become an oncogene due to mutations and cancer. Proto-oncogenes code for proteins that help to regulate cell growth and differentiation. A tumour suppressor gene or antioncogene is a gene that protects a cell from one step on the path to cancer. Cancer develops due to inactivation of a tumour suppressor gene.

Cancer cells typically maintain or increase telomerase activity to achieve immortality, allowing them to divide indefinitely. Inhibiting telomerase production would stop cancer cell proliferation, not promote it.

Genetic mutations are natural occurrences that can happen in any human, not just those with fictional mutant powers. These mutations can be inherited or acquired throughout a person's life.

Congenital diseases are anatomical or physiological abnormalities present since birth, e.g., haemophilia, colour blindness, sickle-cell anaemia, Down's syndrome, Turner's syndrome.

Cystic Fibrosis is a genetic disorder caused by a mutation in the CFTR gene, which leads to the production of defective cystic fibrosis transmembrane conductance regulator (CFTR) protein. This protein is responsible for regulating the flow of salt and water in and out of cells, and its dysfunction results in the buildup of thick, sticky mucus in the lungs and other organs.

Down Syndrome is the most common genetic disorder in the United States, occurring in approximately 1 in every 700 live births. It is caused by the presence of an extra copy of chromosome 21 and is characterized by intellectual disability, distinctive physical features, and an increased risk of certain health problems.

Cystic Fibrosis is an example of a single-gene disorder, meaning that it is caused by a mutation in a single gene. In this case, the mutation is in the CFTR gene, which leads to the production of defective cystic fibrosis transmembrane conductance regulator (CFTR) protein.

Huntington's Disease is an autosomal dominant genetic disorder, meaning that it is caused by a mutation in a gene located on one of the non-sex chromosomes (autosomes). In this case, the mutation is in the HTT gene, and only one copy of the mutated gene is sufficient to cause the disorder.

Sickle Cell Anemia is a genetic disorder caused by a mutation in the HBB gene, which leads to the production of defective beta-globin protein. Beta-globin is a component of hemoglobin, the protein that carries oxygen in red blood cells. The defective beta-globin protein causes red blood cells to become sickle-shaped, leading to various health problems.

Sickle Cell Anemia is the most common genetic disorder among African Americans, affecting approximately 1 in every 12 African American newborns. It is caused by a mutation in the HBB gene, which leads to the production of defective beta-globin protein.